Fuel cell engine shutdown purging system, control method thereof and fuel cell system

Abstract

The invention provides a fuel cell engine shutdown purging system, a control method thereof and a fuel cell system. The purging system comprises a regulating valve, a hydrogen jet, a water diversion piece, a tail exhaust valve, a three-way valve, a hydrogen circulating device, an air outlet throttle valve and an air inlet throttle valve, an inlet I of the regulating valve is connected with a hydrogen source, an inlet II of the regulating valve is connected with a nitrogen source, an outlet of the regulating valve is connected with an inlet I of the hydrogen jet, an outlet of the hydrogen jet is communicated with an anode inlet of a galvanic pile, and an anode outlet of the galvanic pile is connected with an inlet of the water diversion piece; the outlet of the hydrogen circulating device is connected with the inlet of the three-way valve; the outlet of the three-way valve is connected with the inlet of the hydrogen spraying device; the outlet of the three-way valve is connected with the inlet of the air inlet throttle valve; the outlet of the air inlet throttle valve is connected with the cathode inlet of the electric pile; and an inlet of the air outlet throttle valve is connected with a cathode outlet of the electric pile. The cathode and the anode are purged by the same N2 gas source, so that formation of a hydrogen-oxygen interface is avoided.

Description

technical field [0001] The invention relates to the technical field of fuel cells, in particular to a fuel cell engine stop purging system, a control method thereof, and a fuel cell system. Background technique [0002] The proton exchange membrane fuel cell engine system is a power generation device that converts the chemical energy of the reducing agent H¬2 into electrical energy. Since it does not go through combustion, it avoids the limitation of the Carnot cycle, and the energy utilization rate can reach 40%~60%. It avoids the carbides and nitrides produced by combustion, is very friendly to the environment, and is an important way to replace fossil energy. [0003] During the operation of the proton exchange membrane fuel cell engine system in winter (below zero), the cathode of the engine system will produce a large amount of water. Due to the osmosis of water, the water generated by the cathode will move to the anode, and the fuel cell engine system will freeze durin...

AI Technical Summary

Problems solved by technology

The phenomenon of failure due to the freezing of infiltrated water will affect the second start of the engine; if the anode is blown with air, the anode will inevitably form a hydrogen-oxygen interface. At this time, the anode potential will drop significantly, and the cathode potential will decrease. Momentary increase, leading to carbon corrosion

Cause damage to the stack; if the anode is purged with hydrogen, the utilization rate of hydrogen will be reduced, and the formation of hydrogen-oxygen interface cannot be avoided

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